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"""The singleton metaclass for ensuring only one instance of a class.""" |
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import abc |
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from typing import Any |
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class Singleton(abc.ABCMeta, type): |
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"""Singleton metaclass for ensuring only one instance of a class""" |
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_instances = {} |
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def __call__(cls, *args: Any, **kwargs: Any) -> Any: |
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"""Call method for the singleton metaclass""" |
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if cls not in cls._instances: |
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cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs) |
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return cls._instances[cls] |
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class AbstractSingleton(abc.ABC, metaclass=Singleton): |
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"""Abstract singleton class for ensuring only one instance of a class""" |
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pass |
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